Logical reasoning PrepTest 110 · Section 3 · Question 6

Incorrect. While this may be true, it's noted that it's "impossible" to collect samples without getting limestone too so each of these techniques will run into the problem from the stimulus.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Weaken

Stimulus Summary:
Standard archaeological techniques — If an object with vegetable matter has minerals containing carbon, it can't be dated.
Samples — Paint with vegetable matter plus the limestone that it was painted on. It's impossible to get a sample without limestone.
Limestone — A mineral containing carbon
Conclusion — It's impossible to date this paint with standard archaeological techniques

Answer Anticipation:
That first statement establishes a conditional rule. We wrote it out as the contrapositive since it's a bit easier to understand and aligns with the argument better.

After that conditional is established, it brings up a situation to which it applies. There are certain paintings that archaeologists want to date, but they can't get samples without also getting some limestone in it. And limestone triggers the contrapositive of the conditional—it's a mineral with carbon in it, so it prevents the dating of the paint using traditional techniques.

That would seem to justify the conclusion, so it can be hard to spot the assumption in this argument. Whatever the answer is, to weaken this conclusion means to suggest that the standard techniques can be used to date these paintings. Since any sample taken will have limestone in it ("impossible to collect . . . without removing limestone") it must be the case that the limestone can somehow be removed—otherwise there's no way to use standard techniques to date the samples.

Answer Explanation:
The problem stems from the limestone in the samples which is what prevents the dating of the paintings. If procedures exist to remove the problem then it should be possible to use the dating techniques to find the age of the paintings undermining the conclusion.

Key Takeaway:
We think that answer choice (B) is a lot easier to spot when reading it than when trying to anticipate it! The Anticipate step is key to doing well on the exam but you're not always going to succeed at anticipating an answer. Sometimes it's more important to know when you're stuck and to move to the answers. In general if you're spending more than 10—15 seconds stuck and not seeing what's wrong with the argument it's probably time to check to see if the answers can guide you. Sure this might end up with you falling for a trap answer but it's better than staring at the page for a minute and still likely falling for that trap when you still don't have a good anticipation! (Another option is always to skip the question and come back to it later. You'd be surprised how often your brain will see something the second time through!)

Incorrect. Presumably, the limestone that the paintings are on is older than the paintings themselves, so dating the limestone doesn't help with the goal of figuring out the age of the paintings.

Incorrect. The problem wasn't with the paint but with the limestone it's on, so this answer doesn't do anything to the argument.

Incorrect. Minerals containing carbon create problems with the standard archaeological techniques, so it doesn't matter if the proportion of carbon is always the same or changes—any proportion is problematic.